Method of making well pressure sealing cup reinforcing structure

ABSTRACT

An improved reinforcing structure and method of making said structure are disclosed. The improved reinforcing structure is a polyfurcated cylinder having an integral base portion and a tines portion. The method of manufacture includes the steps of rolling a polyfurcated plate with an integral base and tines portion, rolling the base portion into a cylindrical shape and securing the abutting ends of the base.

0 United States Patent 1 1 1111 3,722,053 Berr et al. 1 Mar. 27, 1973 [54] METHOD OF MAKING WELL 1,446,487 2/1923 Timken ..29/163.5 R PRESSURE SEALING CUP 2,619,393 11/1952 Wilson et al.. ..92/24l URE 3,270,697 9/1966 ...2 9/l63.5 R X REINFORCING STRUCT 3,365,775 H1968 Cavagnero et a1. ..29/l63.5 R X [75] Inventors: Robert F. Berry, Dallas; Henry W.

Blackwell Venus t of Primary Examiner-Charles W. Lanham [73] Assignee: Dresser Industries, lric., Dallas, Tex. Assistant Examiner-V. A. DiPalma [22] Filed: July 1971 Attorney-Robert W. Mayer et a1.

[21] Appl. N0.: 166,171 57 ABSTRACT j An improved reinforcing structure and method of [52] US. Cl. ..29/163.5, 29/ l73, 2 9/477, making 1 Said structure are disclosed The improved 29/482 92/241 1 I6 A 5 63 13 1 reinforcing structure is a polyfurcated cylinder having [51] Int Cl 12/16 an integral base portion and a tines portion. The [58] Field 482 method of manufacture includes the steps of rolling a 166/187; 267/181',92/240, 241 113/116 A, 116R,ll6Y,'l16W References Cited 1 1922 Kraft 13/1 16 A polyiurcated plate with an integral base and tines portion, rolling the base'portion into a cylindrical shape and securing the abutting ends of the base.

9 Claims, 6 Drawing figures METHOD OF MAKING WELL PRESSURE SEALING CUP REINFORCING STRUCTURE BACKGROUND OF THE INVENTION lowered into a well by means of a wireline. The tool is 1 lowered through a suitable amount of tubing and then lifted within the well effecting a seal with the pipe and lifting fluid above the tool to the surface. Packer cups are generally used to seal well pressure in one direction and are mounted on a well tool and positioned in a sealing engagement with well pipe. Packer cup application normally is a static or limited movement application.

There are a multitude of prior well swab bodies using a plurality of shaped wires held in base structures of various types-as the reinforcing structure. See, for example, U. S. Pat. No. 2,887,347 issued to T. B. Losey. There are also prior well swabs employing metallic cones or corrugated cylinders as the reinforcing structure. See, for example, U. S.Pat. No. 1,898,292 issued to C. S. Crickmer and U. S. Pat. No. 2,013,903 issued to F. A. Thaheld. There are also prior well swabs employing slotted metallic cylinders as wear protective structures. See, for example, U. S. Pat. No. 2,619,393- issued to R. E. Wilson and J. A. Wilson and U. S. Pat. No. 2,456,551 issued-to R. A. Wilson.

Difficulty has been experienced in the past with such swab cup reinforcing structures constructed with a cylindrical base having upstanding tines or fingers pivotally attached to the base. Lack of cantilevered support from the base allowed the tines to become misaligned during the molding process, or required expensive fixtures and time consuming assembly of each finger.

Disadvantages with other unitary cup reinforcing structures made from tubular material are due to the time consuming machining operations and resultant high cost.

A primary object of this invention is to provide a method and structure for an improved pressure sealing cup reinforcing structure.

A further object is to provide a method and structure for producing a pressure sealing cup reinforcing structure at lower cost.

A further object is to provide an intermediate subassembly reinforcement structure for a well pressure sealing cup.

SUMMARY OF THE INVENTION These and other objects ofthe invention are generally provided by a well pressure sealing cup reinforcing structure having a body with a cylindrical base portion having a non-continuous periphery, the body having a plurality of integral, upstanding tines and by the method including the steps of rolling a polyfurcated plate having an integral base and tines portion rolling the base portion into a cylindrical shape and securing the base portion in the cylindrical shape. As an additional feature, an intermediate subassembly is provided for use in a well pressure sealing cup including a unitary metallic plate with a first edge and an opposite edge and having a continuous portion along the first edge and integral tines extending from the continuous portion to the opposite edge.

2 BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an elevation view of an intermediate subassembly for constructing a well pressure sealing cup reinforcing structure according to this invention.

FIG. 2 is an end elevation view of the subassembly illustrated in FIG. 1.

FIG. 3 is a view partially in elevation and partially in cross section of a well pressure sealing cup reinforcing 0 structure according to this invention.

FIG. 4A is a cross section view of the preferred embodiment taken at section line 4--4 in FIG. 3.

FIG. 4B is an alternative embodiment of FIG. 4A.

FIG. 4C is still another alternative embodiment of" FIG. 4A.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates an intermediate subassembly according to this invention wherein a flat metallic plate of the general shape illustrated may be used to construct the reinforcing structure. The length of a first edge 10 is determined as the approximate circumference for the base of the cup to be more fully described hereinafter. The opposite edge I4 from the first edge 10 is the starting point for sheared or sawed slots 16 which begin at opposite edge 14 and proceed to a point 18 near the first edge 10. With proper tooling known to those skilled in the art, all of the necessary multiplicity of slits 16 can be sheared or cut with a single stroke of a punch press although many other methods of manufacture are well known to those with skill in the art.

FIG. 2 illustrates an end view of the semi-finished structure in FIG. 1 after bends running parallel to the edge 10 have been performed. Bend 20 and bend 22 achieve an offset from continuous portion 24 of plate 8 to a straight portion 26 of the tines 28 which were formed by slits 16. A bend 30 positions surface 32 on tine 28 at an angle which provides a chamfer or an angular lead on surface to guide the resulting pressure sealing cup past joints, shoulders and other irregularities in the pipe (not shown) in which the cup will seal.

FIG. 3 illustrates a semi-finished reinforcing structure after continuous portion 24 has been rolled into a generally cylindrical shape. The outside diameter of cylindrical shape of continuous surface 24 is illustrated at 24 in FIG. 3. Straight portion 26 of the tines may be oriented parallel to central axis 34 or at an angle a of 0 to 15. Since the straight portion 26 is on a larger diameter than continuous portion 24, after forming continuous portion 24 into a cylindrical surface, there will be gaps between the tines since the circumference at a larger diameter 35 is greater than the circumference at diameter 24. The circumferential length of metal at diameter 35 will be equal to the circumferential length of metal at diameter 24. However, since the circumference at diameter 35 is greater than the circumference at diameter 24, there will be circumferential gaps at diameter 35 since the tine or metallic portion will subtend a smaller angle of are at the larger diameter than the same width of metal at the diameter at surface 24. The slots or gaps between the tines provide for exposure of the elastomer as subsequently molded around the reinforcing structure according to this invention whereby the elastomer may feed through the slots between the tines responsive to pressure internal to the cup to maintain a seal between the cup and the pipe in which it seals while the cup may be performing in a static condition as a packer cup or in a dynamic condition as a swab cup. A cylindrical ring 36 may be placed in encircling relationship to cylindrical surface 24 to reinforce the structure and contain the base to prevent outward movement responsive to internal pressure in the finished cup. Tines 28 are thus cantilevered from continuous portion 24 and are flexible at the free end 38 which was originally the opposite edge 14 in FIG. 1.

American Petroleum Institute (API) tubing and casing threads represent the largest usage of threaded connections used in oil and gas wells. The basic distance is 1 inch between the ends-of two pieces of pipe with API tubing or casing threads threaded into a coupling and tightened with the proper torque. Manufacturing tolerances can allow a particular joint dimension to vary plus or minus 0.5 inches, i.e. between 0.5 and 1.5v

inches. Since the maximum allowable distance between the end of pipes in a joint is 1.5 inches, the straight portion of a well pressure sealing cup should beat least 1.5 inches so the cup may enter the'end of one piece of pipe before leaving the end of the adjacent piece of pipe. A cup too short to span the gap between pipes could move laterally into the larger inside diameter of 'the coupling and allow the cup to become hung in the gap and could allow the cup to lose sealing engagement with the pipe.

FIG. 4A illustrates the section 4-4 of FIG. 3. In FIG. 1, ends 42 and 44 ofcontinuous portion 24 are brought together as illustrated in FIG. 4A at joint 40. In this embodiment the continuous portion 24 is rolled into a substantially 360 cylindrical surface to form thereinforcing structure for a pressure sealing well packer cup or swab cup. The joint 40 may subsequently be reinforced by the continuous ring 36 or it may be welded together.

DESCRIPTION OF ALTERNATE EMBODIMENTS FIG. 4B illustrates an alternate embodiment in which a plate with a first edge long enough to form onehalf the circumference of the base of a reinforcing structure is used. Two such base segments may, each be formed into a 180 of cylindrical arc and then assembled with twojoints as at 46 and 48 in FIG. 48 to form a completed reinforcing structure. Joints 46'and 48 may be reinforced by the addition of a ring 36 or each joint may be welded.

FiG. 4C illustrates another alternative in which each piece of reinforcing structure forms one-third of the base circumference so that three pieces are used to form a completed structure. The three segments are then assembled with three joints as at '50, 52, and 54 and may be reinforced by addition of ring 36. Alternative embodiments as illustrated in FIGS. 48 and 4C may lend themselves more readily to single stroke forming in a punch press operation and thereby offer economies of manufacture.

After considering these examples, skilled persons will understand that variations may be made without departing from the principles disclosed and I contemplate the employment of any structures, arrangement,

or modes of manufacture that are properly within the sco e of the appended claims.

e embodiments of the invention in which an excluincludes welding said ends of said base portion in abutting relation.

3. The method of claim 1 wherein said securing step comprises placing an annular ring around said rolled base portion. v

4. The method of claim 1 wherein'said securing step comprises welding a portion of an annular ring across the abutting ends of said rolled base portion.

'5. A method of making a reinforcing structure for-a well swab body comprising:

slitting a metallic plate whereby a plurality of substantially uniformly shaped tines are formed in said plate wherein said tines-extend over a major portion of the full width of said plate and are integral with an unslit base portion of said plate; rolling said slit plate whereby said unslit base portion of said plate is rolled into a cylindrical shape; and securing the ends of the unslit base portion of said plate after rolling whereby the cylindrical shape is retained. v

6. The method of claim 5 further comprising the step of forming said slit plate into a predetermined shape prior to said rolling step.

7. The method of claim 5 comprising the further step of forming said rolled plate whereby said tines portion is formed into a predetermined shape before said securing step. i

8. The method of claim 5 comprising the further step of forming the tinesportion of said plate into a predetermined shape after said securing step.

9. The method of claim 5 wherein said securing step includes welding the ends of said unslit base portion.

8 t i i l 

1. A method of making an improved reinforcing structure for a well swab body comprising: rolling a polyfurcated plate having integral base and tines portions whereby said base portion is rolled into a cylindrical shape; and securing the ends of said base portion in abutting relation whereby said rolled base portion remains in a cylindrical shape.
 2. The method of claim 1 wherein said securing step includes welding said ends of said base portion in abutting relation.
 3. The method of claim 1 wherein said securing step comprises placing an annular ring around said rolled base portion.
 4. The method of claim 1 wherein said securing step comprises welding a portion of an annular ring across the abutting ends of said rolled base portion.
 5. A method of making a reinforcing structure for a well swab body comprising: slitting a metallic plate whereby a plUrality of substantially uniformly shaped tines are formed in said plate wherein said tines extend over a major portion of the full width of said plate and are integral with an unslit base portion of said plate; rolling said slit plate whereby said unslit base portion of said plate is rolled into a cylindrical shape; and securing the ends of the unslit base portion of said plate after rolling whereby the cylindrical shape is retained.
 6. The method of claim 5 further comprising the step of forming said slit plate into a predetermined shape prior to said rolling step.
 7. The method of claim 5 comprising the further step of forming said rolled plate whereby said tines portion is formed into a predetermined shape before said securing step.
 8. The method of claim 5 comprising the further step of forming the tines portion of said plate into a predetermined shape after said securing step.
 9. The method of claim 5 wherein said securing step includes welding the ends of said unslit base portion. 